ardour/ardour
ardour
/
ardour
13
1
Fork 0
Code Pull Requests Releases Activity

Prevent race between adding ports and IO port-lookup

This commit is contained in:
Robin Gareus 2020-04-26 22:17:18 +02:00
parent 31c39ed869
commit b0daa85bfb
Signed by: rgareus
GPG Key ID: A090BCE02CF57F04
1 changed files with 18 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
libs/ardour/session.cc
View File

@ -6549,6 +6549,18 @@ Session::update_latency (bool playback)
reverse (r->begin(), r->end());
}
/* Session::new_midi_track -> Route::add_processors -> Delivery::configure_io
* -> IO::ensure_ports -> PortManager::register_output_port
* may run currently (adding many ports) while the backend
* already emits AudioEngine::latency_callback() for previously
* added ports.
*
* Route::set_public_port_latencies() -> IO::latency may try
* to lookup ports that don't yet exist.
* IO::* uses BLOCK_PROCESS_CALLBACK to prevent concurrency,
* so the same has to be done here to prevent a race.
*/
Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
samplecnt_t latency = (*i)->set_private_port_latencies (playback);
(*i)->set_public_port_latencies (latency, playback);
@ -6560,15 +6572,20 @@ Session::update_latency (bool playback)
* With internal backends, AudioEngine::latency_callback () -> this method
* is called from the main_process_thread (so the lock is not contended).
* However jack2 can concurrently process and reconfigure port latencies.
* -> keep the process-lock.
*/
Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
/* prevent any concurrent latency updates */
Glib::Threads::Mutex::Lock lx (_update_latency_lock);
set_worst_output_latency ();
update_route_latency (true, /*apply_to_delayline*/ true);
/* relese before emiting signals */
lm.release ();
} else {
/* process lock is not needed to update worst-case latency */
lm.release ();
Glib::Threads::Mutex::Lock lx (_update_latency_lock);
set_worst_input_latency ();
update_route_latency (false, false);